Azo dye.



UNITED STATES PATEN onnion iLEoPoL nnssn nun oscnncunrnnn, or nnnnnrnrlnnnn ARTHUR 2am, on VOH- WINKEL, NEAR ELBERIEELD, enmymny nssrenons TO 'FARBENFABRIKEN vomvr.

FRIEDR. BAYER & 00., or ELBEREELD, GERMANY,- A CORPORATION or GERMANY.

Azo bis. 1

933,448. 7 Specification of Iet te rs P atent, No Drawing. Application filed April 8-, 1909.

1 Patented Sept. 7,1909. Serial No. 488,700.

To all whom it may concern: Y I

Be it known that we, LEOPOLD Hnssn, OSCAR GtiNTHER, and ARTHUR ZART, doctors of philosophy, chemists, citizens of theGerman Empire, residing at, respectively, Elberfeld, and V ohwinkel, nearElberfeld, Kingdom of Prussia, Germany, have invented new and useful Improvements in Azo Dyestuffs, of which the following is a specification.

Our present invention relates to the manu-' facture and production of new secondary disazo dyestuffs dyeing cotton from red to blue shades which are remarkable for their extraordinary fastness to light.

The new dyes are obtained by first pro ducing aminoazo compounds from diazotized amins of the benzene series containing a negative group in ortho-position to the amino-group with suitable amins, then diazotizing these intermediate products and combining the thus produced diazoazo compounds with 2-amino-5-naphthol compounds having the formula:

a/v'w alkaline salts dark powders easily soluble in water. Upon reduction with stannous chlorid and hydrochloric acid-the dyestuffs are decomposed, an ortho-substituted' amin, a diamin and a derivative of a 2.6-diamino-5- naphthol compound having the formula:

(X meaning hydrogen or SO H) are ob- The new dyestuffs are in the'shape of their tained. They dissolve in concentrated sul .furic acid with from a violet to green color.

In order to carry out this process we can 6. 9. proceed as follows, the parts being by weight:- 173.5 parts of anilin-ortho-sulfonic acid are diazotized with 69 parts of sodium nitrite and the necessary quantity of hydrochloric acid and the diazo compound thus produced is then combined With 156.5 parts of para-Xylidin hydrochlorid in the usual way with the addition of sodium acetate, the intermediate compound is redissolved in water and is then rediazotized at 1520 C., the diazo compound is salted out and filtered off. It is stirred up with Water to a paste and is added to a solution of 363 parts of 2-amino-5-naphthol-1.7-disulfonic acid containing an excess of sodium carbonate. The dyestuff is then isolated in the usual way. It is after being dried and pulverized in the shape of its sodium salt a dark green powder soluble in water with a red color and soluble in concentrated sulfuric acid with a greenish-blue color. By reduction with stannous chlorid and hydrochloric acid the dye is decomposed anilin ortho sulfonic acid, 2.5- dimethyl-l.t-diamino-benzene and 2.6-diamino-5-naphthol-1.7-disulfonic acid are formed. Itdyes cotton fast bluish-reddish shades.

The process is carried out in an analogous manner on starting from other amins containing a negative group in ortho-position to the amino-group, such as para-toluidilr ortho-sulfonic acid, meta-Xylidin-ortho-sulfonic acid, .para-chloroanilin-ortho-sulfonic acid, para nitranilin ortho sulfonic acid, anilin-2.4c-disulfonic acid, ortho-nitranilinpara-sulfonic acid, or on using other middle components to form the aminoazo compounds, such as anilin, cresidin, alpha-naphthylamin-G- or 7-sulfonic acid, alpha-naphthylamin, or on using 2.5.7-aminonaphthol sulfonic acid as end component.

We claim:

1. The herein described new azo dyestuffs obtainable from aminoazo compounds which contain in the first component which is a benzene compound a negative group in orthoposition to the amino-group with the hereinbefore defined 2 amino 5 naphthol compounds, which dyestuffs are, after being dried and pulverized, in the shape of their alkaline salts dark powders soluble in water,

soluble in concentrated sulfuric acid with from violet to green-color; yielding-upon reduction with sta-nnouschlorid and hydr0-- chloric acid an ortho=subst ituted amin of the benzene series, a 'diamin and a derivative of a 2.6-diamino-5-naphthol compound of the and dyeing cotton from red to blue shades; substantially" as de Y 'rset ourihands inthe presence of two subabove given formula scribed. v

2. The herein described new azo dyestu'ff I whichcanbe obtained-from anilin ortho-sulionic; acid, para-Xylidin and 2-a1nino 5-naph thol-lfZ-disulfoniciacid, which dyestuff l is, after, being dried and :pulv'erized, in the shape'oi its sodium salta dark green powder and in concentrated sulfuric acid with a greenislrblue color yielding upon reduction with stannons chlorid and hydrochloric acid anilin ortho sulfonic acid-,- 2-.5-di1nethy'l-L4 diaininobenzene and 2.6 diainino 5 naphtliOT-L'T-disulfonic acid; and dyeing cotton -bluish-red shades, substantially as described. Ifite's t irnony' whereof we have hereunto scribing witnesses.

LEO POLD HE SSE it. s]

.. OSCAR oI'iNTHER.v 11. 3.

ZARII. -[L. s] Vitnesses y 

